3D Fine Characterization and Single-Well Simulation Analysis of Fractured Wells
The single-well simulation for fractured vertical or horizontal wells is mainly conducted based on two-dimensional or quasi-three-dimensional grids,which,however,cannot accurately characterize the 3D spatial morphology of fractures and wellbores.In this paper,a CAD-based 3D geometric modeling method of fractured wells,a grid node constraint algorithm adapting to fracture morphology and spatial flow characteristics,and a grid-scale optimization method were proposed.Then,semi-structured grids were used to build a 3D inner boundary model of fractured well,simplifying and unifying the production calculation equations for fractured vertical and hor-izontal wells.Based on the differences in flow characteristics of matrix and fractures,a coupled two-point and multi-point flux approximation method was used for numerical solution.Finally,a single-well simulation was con-ducted on a fractured vertical well in a multilayer reservoir with complex fracture networks.The results show that the differences in physical properties of layers have a significant impact on the pressure distribution of hydraulic fractures in the layers,and the geometric shape and size of hydraulic fractures as well as the physical parameters of the layers are important factors affecting the spatial distribution of pressure.The study results are of practical signif-icance for improving the 3D fine characterization capacity and single-well simulation accuracy of complex fractured wells.
fractured wellfine characterization3D semi-structured gridsingle-well simulationmultilay-er fracture networks reservoirspatial distribution of pressure